Rosemary

Rosemary is grown in home gardens, commercial herb operations, and landscape plantings, valued both for its culinary leaves and its ornamental, drought-tolerant habit.

As a woody perennial, rosemary can remain productive for many years, though older plants may become leggy and benefit from periodic pruning or replacement.

Family

Lamiaceae (mint family)

Genus

Salvia (formerly Rosmarinus)

Principal species

Salvia rosmarinus

Growth habit

Evergreen woody shrub with narrow, needle-like aromatic leaves and small blue to white flowers

Rosemary is native to the Mediterranean coast, where it grows wild on rocky, sunny slopes. It has been cultivated as a culinary and aromatic plant since antiquity and is now grown widely across temperate and Mediterranean-climate regions worldwide.

Commercial production for fresh, dried, and essential-oil markets is found across Mediterranean Europe, North Africa, and other regions with a compatible climate.

Rosemary is woody and long-lived where winters allow, and a planting is expected to crop for several years rather than being resown. That changes the establishment decision: spacing, drainage and cultivar hardiness are settled once, and a stand lost to a wet winter or a hard frost is a multi-year loss rather than a season's.

Well-drained sandy loams and loams of low to moderate fertility, including alkaline soils, suit rosemary well; poorly drained or heavy clay soils increase the risk of root disease.

• Propagation mainly by cuttings, since named cultivars do not come true from seed
• Regular light pruning after flowering to maintain compact, productive growth
• Wide spacing on well-drained sites to reduce humidity and disease pressure
• Winter protection or container culture in climates with hard frosts, depending on cultivar hardiness

Rosemary generally requires modest fertility, and excessive nitrogen can encourage soft, leggy growth that is more prone to pest damage and less aromatic.

Rosemary roots deeply for a subshrub and, once a plant has made that root system, it draws on soil water a shallow-rooted herb cannot reach. Growers who irrigate it on a vegetable schedule lose plants: the species evolved on thin, sharply drained Mediterranean soils and its roots do not tolerate sitting wet. Where irrigation is used it is applied rarely and deeply rather than often and lightly.

Where irrigation is used, drip systems help maintain the good drainage rosemary requires while avoiding prolonged foliage wetness.

Root rot is the primary disease risk, occurring on poorly drained or overwatered sites, and powdery mildew can affect foliage under humid conditions. Spider mites and aphids are common pests of rosemary foliage.

Sprigs and leaves are cut by hand as needed throughout the growing season, with fresh material used directly or dried and stripped from woody stems for storage.

• Fresh and dried leaves used widely as a culinary herb, particularly with roasted meats and vegetables
• Essential oil extracted for the flavor and fragrance industries
• Dried herb blends and seasoning products
• Ornamental and landscape use, including as an informal hedge in suitable climates